1. Field of the Invention
This invention relates to carbonaceous fuel particles and method for making same, particularly for making such particles containing fertile or fissile materials.
2. The Prior Art
The most promising or advantageous fuels for high efficiency nuclear power plants or for rocket propulsion have included non-graphite, spherical fuel particles made from sol-gel such as uranium carbide spheres (UC.sub.2). Fuel made of such spherical particles however has a molten temperature at about 2654.degree. C. and thus needs to operate below, eg. 2200.degree. C. to avoid significant deformation.
Attempts have been made to find a nuclear fuel that has a significantly higher melting temperature, to reduce the threat of melting and to achieve greater engine efficiency, e.g. for a gas turbine or for improved rocket engine specific impulse. Accordingly there is a need and market for such improved higher temperature nuclear fuel that lessens or obviates the above prior art shortcomings.
There has now been discovered a nuclear fuel that has a significantly higher melting temperature than seen in the prior art and that concurrently can provide for greater efficiency of nuclear engine operation, including that of gas turbines and rocket engines for space vehicles.
In related prior art, U.S. Pat. No. 4,035,452 to Davis et al (1977) discloses impregnating fuel particles with polymer, adding nuclear fuel and then joining the particles into a cohesive mass with a carbonaceous binder. U.S. Pat. No. 4,963,758 to Noren (1990) and U.S. Pat. No. 5,037,606 to DeVelasco, et al (1991) disclose coatings for fuel spheres made by others.
In further prior art, an Article entitled "Preparation of carbon microbeads containing fine platinum particles from aqua-mesophase" Oct. 8, 1991, "Letters to the Editor" in Carbon, vol. 30, 1992 at pp. 120 & 122 by K Esumi, et al., discloses adding platinum to spheres made from aqua-mesophase in silicone oil for use, e.g. as a catalyst. Such microbeads are then heated to 1000.degree. C. to form carbon microbeads. There is no suggestion of preparing a fuel from such process, nor are carbon microbeads converted to graphite microbeads and the size of the microbeads ranges from 10-20 microns.